VISION AIDS

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How to insert, remove and clean your contact lenses

Different ways to insert and remove your contact lenses

FAQs

EYE TEST

A visual field examination is a test designed to find out how well your peripheral vision is functioning. Reading an eye chart tests how well your visual system is working in the central area but provides little information about your side vision. A visual field examination tests both your central vision and your peripheral vision by measuring the sensitivity of your visual system in various positions.

Why is peripheral vision important?

Central vision allows you to see the fine details of the objects at which you are looking directly but peripheral vision is used to find objects and detect threats, and is important for general orienta­tion and balance. For example, if you have poor vision on one side, you may tend to bump into doorframes and driving may be very dangerous if you cannot see traffic in the next lane.

In sport, peripheral vision is necessary to be able to locate other players on a court or field and to see the ball out of the corner of your eye.

Peripheral vision is also important For other tasks such as reading. A person with poor vision on the right side may find it difficult to read a line of type, as they cannot see the next word in the line. A person with poor vision on the left side may be able to read along the line but can have problems finding the start of the next line.

What causes visual field defects?

Visual field defects can be caused by anything that damages or interferes with any part of the visual system. Causes of visual field defects include injuries or diseases of the retina (the light­sensitive layer of cells at the back of the eye), and diseases such as glaucoma, which damage the optic nerve that carries signals from the eye lo the brain. Other causes are strokes and other brain injuries that damage the regions of the brain involved with processing vision.

Damage to different parts of the visual system causes different types of visual field defects. This makes visual field examinations a very useful way of detecting and diagnosing many diseases.

How does a visual field examination work? There are several ways of testing visual fields but most commonly a computerised instrument called an automated perimeter is used. This consists of a concave bowl with a system that allows lights to be flashed at various points inside the bowl. The brightness of the lights varies and is controlled by a computer.

When your visual fields are being tested, you sit facing into the bowl with your head resting on a support so that your head will not move. One eye at a time is tested, so an eye-patch is worn over the eye not being tested. You look directly at a light in the centre of the bowl and press a button any lime you see a light flash elsewhere in the bowl. The computer varies the bright­ness of the test lights and notes whether you saw the lights and responded by pressing the button. This allows the sensitivity of the visual system at each point to be measured.

Tips for visual field examinations

Remember to keep looking at the light in the centre of the bowl. This will keep your eye still. If your eye is moving around, it is not possible to tell which part of the visual field is being tested.

Do not worry if you do not seem to be seeing many lights.

To test the sensitivity of your visual system, the instrument has to

flash some lights that are too dim for you to see. A person with completely normal visual fields usually will not see about one­third of the lights.

Press the response button any time you think you see a light in the bowl. It is better to respond immediately, even if you are wrong, than to be too cautious and not press the button when the light flashes.

Remember to blink occasionally to ensure that your eyes do not become dry. The best time to blink is just after you have pressed the button to show that you saw a light flash. There will be a short delay before the next light is presented.

Medicare rebate

The Federal Government recognises the importance of visual field testing for the long-term health of your eyes and pays a Medicare benefit for examinations.

Please bring a copy of your old prescription or your current glasses and a list of your medications.

If you are coming in for a full test we may also want to dilate your pupils, so it is a good idea to bring sunglasses and a driver, or plan to spend about an hour after your test before driving.
If you are coming in for a contact lens aftercare, please wear your contact lenses; but bring your glasses and a contact lens case as we will probably need to take them out during the consultation.

The first is a local anaesthetic, which will make your eyes numb for about 15 mins and the second is yellow dye. We use these first two drops to check the pressure in your eyes and also the health of the front surface of your eyes.
The last drop is the one that dilates your pupils so we can properly check on the health inside of the back of your eye; this is the drop that makes things a bit fuzzy and a bit blurry.

CHILDREN’S EYE TESTS

Children often don’t know that there is anything wrong with their vision as they assume everyone sees the same way they do.
They also find it easier to compensate for any difficulties they may be having, however this can lead to headaches and eyestrain.

There are many signs to look for with children’s vision, including;
– eyes that turn in or out
– holding print in or out to try and focus
– difficulty learning to read
– headaches
– blurred or double visionIf you have any of these concerns or others, the easiest thing to do is to book your child in for a comprehensive eye examination to be sure that all is well.

CONTACT LENSES

There are now contact lenses to suit most spectacle prescriptions, even for those who just wear glasses for reading.
There are other factors that determine your suitablilty for contact lenses, such as the shape of your eye and the stability of your tear film.
The best option is to come and have a consultation with an optometrist who will look at the health of your eyes as well as your prescription and lifestyle and then be able to let you know what sort of contact lenses, if appropriate, will suit you best.

OrthoK is a relatively new type of hard contact lens that is worn to bed and removed first thing in the morning.
Once the lens is removed, the person has clear vision for 1-2 days before needing to wear the lens again overnight.
This unique type of lens reshapes the cornea, to allow for clear vision.
Recent research has also shown that these help slow or stop the progression of myopia/short sightedness in children.
If properly maintained, the lenses can last for 5-10 years, meaning that it can be a very economical option as well.

If there has been a change in your prescription it will often take a little while for your brain to adapt to the new prescription. The bigger the change, the longer it will take.

If you still can’t see clearly, try having the glasses adjusted by one of our dispensers to make sure they’re sitting correctly. If they are, persevere for 2 weeks or so, trying only to wear your new glasses rather than any old pairs.

If you still cannot adapt or cannot or cannot see at all clearly, please come in and have one of our optometrists re-check your prescription.

EYE HEALTH

Glaucoma is often called the ‘sneak thief of sight’ because it is a condition that gradually whittles away vision from the edges inwards. By the time anyone notices, a significant amount of vision loss has occurred.

In glaucoma, nerve cells that transmit information from the eye to the brain become damaged. Even though the eye may be capturing images, the nerve that sends the signal lo the brain is defective. This causes a disruption in visual processing, result­ing in ‘blind spots’ that, if untreated, can lead to tunnel-vision and blindness.

What causes glaucoma?

Glaucoma is often associated with increased pressure inside the eye, which can cause physical damage to nerve cells. Several forms of glaucoma occur with normal or even low eye pressure. The chances of developing glaucoma are greatly increased by risk factors that include:

Age

Glaucoma becomes more prevalent as we age, with one in 12 people aged over 80 years having the disease.

Family history

Glaucoma can run in families. There is a higher risk of developing the disease if an immediate Family member has been diagnosed with glaucoma.

Myopia (shortsightedness)

Certain kinds of glaucoma are more prevalent in people who are shortsighted.

Diabetes

Diabetes may be associated with glaucoma, or may cause physi­cal changes to the eye that result in glaucoma.

Can glaucoma be prevented?

Most cases of glaucoma cannot be prevented and vision loss from glaucoma is considered to be irreversible. Early detection and treatment are the best ways to control glaucoma.

What are the symptoms?

Symptoms of glaucoma can be very subtle so it usually goes undetected until the very late stages of the disease. Glaucoma typically causes no pain or discomfort, and does not affect central vision, so unlike other eye diseases, there is nothing to prompt someone to seek an eye exominotion.

As glaucoma progresses, sufferers may find that they tend to bump into things, or notice that they have poor peripheral vision, perhaps while driving. Some types of glaucoma can cause intense eye pain that requires emergency treatment but this is very rare.

How does an optometrist diagnose glaucoma?

Your optometrist will need to ask you questions about your health and ocular history and perform a series of tests to diagnose glau­coma. These tests may involve the optometrist looking at the nerve fibres at the bock of the eye, assessing the drainage network of the eyes, measuring the pressure inside the eyes with a special

instrument called a tonometer and measuring the thickness of the eye surface. Your optometrist may also toke a photograph of the retina at the bock of your eye or ask you to have a visual field test. All of these tests are simple and painless.

How is glaucoma treated?

Prescription eye-drops are usually the first line of treatment against glaucoma. Once diagnosed, glaucoma management becomes a life-long commitment. A shared-care arrongement between an optometrist and ophthalmologist makes it easier for people with glaucoma to be checked regularly and have their treatment altered if necessary. Sometimes, eye-drops alone are not sufficient to control glaucoma progression and special laser treatment or surgery may be required.

Glaucoma and regular eye examinations

In developed countries, modern examination techniques and treat­ment mean that glaucoma seldom causes absolute blindness. Even so, more than 300,000 Australians have glaucoma and only half of these people are aware that they have the disease. Regular eye examinations are your best protection against vision loss from glaucoma, especially if you are aged over 40 years.

Glaucoma Australia

Glaucoma Australia is a national, not-for-profit organisation dedicated to providing educational services to raise aware­ness about glaucoma, to support glaucoma sufferers and to raise funds for research.

For more information about glaucoma call Glaucoma Australia on 1800 500 880 or visit www.glaucoma.org.au

Cataracts are a cloudiness that form in the lens of the eye. The lens normally is clear. Poor vision results because the cloudiness interferes with light entering the eye.

Are cataracts a kind of growth?

No. Cataracts are due to a change in the lens material.

What causes cataracts?

Most cataracts are a result of ageing and long-term exposure to ultraviolet light. Some are caused by injury and certain diseases and in rare cases by exposure to toxic materials and radiation.
Occasionally cataracts are present at birth, due to the baby’s mother having had rubella during the pregnancy, or genetic defects.

Do cataracts get worse?

Yes. The clouded areas become larger and dense and cause the patient’s sight to become worse. The time taken for this to happen varies from a few months to many years.

Do cataracts affect both eyes?

Usually cataracts affect both eyes but often develop at different rates in each eye.

How common are cataracts?

People older than 65 years often have signs of cataracts and should have their eyes examined regularly.

Can cataracts cause blindness?

If untreated, cataracts can cause blindness. Blindness can be prevented by detecting the cataracts early and, if necessary, by having them removed surgically.

How well will I see if my lens is removed?

In most cases very well. Most patients have an intra-ocular lens (IOL) ) inserted at the time of surgery, with excellent results. This is a plastic lens which replaces your own cloudy lens. Patients may also need to wear spectacles or contact lenses.

What are the signs of cataracts?

Usually the development of cataracts is gradual with a painless worsening of sight. Other symptoms include blurred or hazy vision, spots before the eyes, double vision and a marked increase in sensitivity to glare.

How can I be sure I don’t have cataracts?

An examination by your optometrist will reveal any changes that have occurred in the lens of the eye. Optometrists have special equipment which enables them to see changes in the lens which may
lead to cataracts several years before any symptoms appear.

Can cataracts be prevented?

There is no proven method of preventing cataracts. Long-term exposure to ultraviolet light is thought to induce cataracts, so a brimmed hat and approved sunglasses should be worn in sunlight.

When should I have a cataract operation?

This varies with each patient. Usually cataract surgery is performed when the patient’s vision interferes with daily life. Your optometrist will assist you in making this decision.

Is cataract removal a major operation?

Cataract surgery is now a relatively minor procedure. Often it is performed under a local anaesthetic. Depending on the patient, the surgery may be performed on an out-patient basis. This means that the patient attends a hospital or clinic for the surgery and is able to go home the same day. The surgery is performed by an ophthalmologist, a medical doctor who specalises in eye surgery.
Your optometrist will refer you to an ophthalmologist if necessary.

Age-related maculopathy (ARM), also known as senile macular degeneration, is damage or breakdown of the macula. The macula is a very small part of the retina, the light-sensitive tissue of the eye, which is responsible for central vision. This is the part of the retina which produces the finest detailed vision.

How does ARM affect vision?

As ARM damages the part of the retina responsible for central vision and for seeing fine detail, it becomes difficult to see small details of objects. Vision to the sides is not affected. If both eyes are affected, reading and other tasks requiring fine vision may become very difficult. ARM does not cause blindness. Because some side vision remains, usually people can still take care of themselves.

What causes ARM?

ARM is the result of ageing processes in the eye. Some of the layers of the retina thicken and waste material which is usually removed from the retina forms deposits, distorting the retina. This distortion can cause damage to the other layers of the retina. In about 10 per cent of cases, new blood vessels grow into the macula from beneath.
These newly formed vessels are fragile and often leak blood into the retina where it causes scar tissue to form. The scarring blocks out central vision to a severe degree. There are also some other forms of macular degeneration which are inherited and not associated with ageing.

How common is ARM?

ARM mainly affects older people: about four per cent of those more than 40 years old, nine per cent of those over 50 years, 23 per cent of those over 65 years and 31 per cent of those aged 80 years or more. Men and women are equally affected. ARM accounts for up to 45 per cent of legal blindness and up to 70 per cent of seriously impaired vision in people over the age of 70 years.

How is ARM detected and diagnosed?

People with ARM may notice that their vision has deteriorated. Many patients do not realise that they have a problem until their vision becomes blurred. Optometrists perform a number of tests in an examination which enables them to detect the presence of ARM in the early stages.

The optometrist examines the macula carefully with an instrument called an ophthalmoscope which allows examination of the interior of the eye. Sometimes the optometrist may place a drop in the eye to dilate the pupil to get a better view of the internal structures. Through the ophthalmoscope the optometrist will look for changes in the structure of the macula such as accumulations of waste material or new blood vessels.

Another test which may be used is a grid pattern known as an Amsler chart. This is a regular grid which looks like a piece of graph paper. Patients with ARM often report that sections of the grid appear to be distorted or missing.

Optometrists will usually refer patients whom they suspect have ARM to an ophthalmologist (eye surgeon) for confirmation of the diagnosis. The ophthalmologist will perform a test called fluorescein angiography. In this test a fluorescent dye is injected into the patient’s bloodstream and the ophthalmologist observes the progress of the dye through the blood vessels in the retina. This reveals any leaking blood vessels.

Can ARM be treated?

When most body tissues such as muscle, skin or bone are damaged, the tissues’ cells have the capacity to regrow and repair the damage. Because nerve cells cannot regenerate, damage to nerve tissue, such as the retina, is usually permanent and irreversible. This is why the vision loss in ARM is so difficult to treat, compared with other vision disorders. For example, it is possible to remove and replace the eye’s lens in a person with cataract but it is not possible to replace or even repair the retina of a person with ARM

Where new blood vessels have appeared in the macula area, laser surgery may be used. In this treatment a focused, intense beam of laser light is used to seal off leaking blood vessels and to prevent new vessels growing. This treatment is most effective when it is applied in the very early stages of the disease, before extensive damage has been done.

While there is little which can be done to prevent or cure ARM, people with the disease can be helped to continue functioning normally. Many patients with ARM will eventually come under the classification of being a low vision patient. Special help in the form of low vision aids is available from optometrists and specialist low vision clinics. Low vision aids enable patients to make the most of their vision and include devices such as miniature telescopes, high-powered reading spectacles, hand-held and stand magnifiers, closed circuit televisions and other simpler aids such as large-print books.

What should you do about ARM?

For treatment of ARM to be effective, it must be diagnosed as early as possible. Regular eye examinations are the key to early detection of retinal changes and other signs of disease. If you notice any change in the quality of your vision, have your eyes examined immediately. Regular examinations are particularly important for people over the age of 50 years and people whose families have a history of eye problems.

Recent studies have shown that wearing good quality sunglasses and taking daily antioxidant supplements reduce the incidence and severity of ARM.

Like a camera, your eye needs to focus differently to see objects up close as opposed to those far away.
The lens inside your eye is flexible so that you can pull it into shape to see things close up, and relax to look in the distance.

The lens is a living tissue, so as you get older it grows and puts on extra layers like an onion.
This makes it fatter and stiffer, so you can’t change focus to look as things close up like you used to be able to.

20/20 vision is a term used to express normal visual acuity (the clarity or sharpness of vision) measured at a distance of 20 feet. If you have 20/20 vision, you can see clearly at 20 feet what should normally be seen at that distance. If you have 20/100 vision, it means that you must be as close as 20 feet to see what a person with normal vision can see at 100 feet.

20/20 does not necessarily mean perfect vision. 20/20 vision only indicates the sharpness or clarity of vision at a distance. There are other important vision skills, including peripheral awareness or side vision, eye coordination, depth perception, focusing ability and color vision that contribute to your overall visual ability.

Some people can see well at a distance, but are unable to bring nearer objects into focus. This condition can be caused by hyperopia (farsightedness) or presbyopia (loss of focusing ability). Others can see items that are close, but cannot see those far away. This condition may be caused by myopia (nearsightedness).

A comprehensive eye examination by a doctor of optometry can diagnose those causes, if any, that are affecting your ability to see well. In most cases, your optometrist can prescribe glasses, contact lenses or a vision therapy program that will help improve your vision. If the reduced vision is due to an eye disease, the use of ocular medication or other treatment may be used.